Sunday, January 08, 2006
Inside Dope by Dick Tracy: Cannabis Psychosis, Marijuana Munchies,The Sativex Papers and Does Marijuana Make Your Brain Grow
'Where there's smoke ..' by Blake Morrison, was published as a five-page cover story in the G2 supplement of The Guardian (Friday December 16, 2005). The pitch was as follows: 'When the government last year downgraded it to a class C drug, the message seemed pretty clear: cannabis is harmless. Since then, there has been mounting evidence of a link between the drug and mental illness. So is it safe to skin up?'
The history of cannabis and cannabis prohibition is, of course, littered with scare stories that have been used, at various points in history, to demonise the drug for political reasons. Yet this time we are being asked to believe that this is the proverbial horse of different colour by such prominent spokeswomen as columnist Sue Arnold (who in 1997 extolled the wonders of cannabis after it temporarily cured her eye-condition (retinitis pigmentosa) but went through a volte face when her son had a psychotic incident after smoking skunk and spent six m0nths in hospital) and Rosie Boycott (who memorably led a legalise cannabis campaign when she was editing The Independent but, more recently, has made a tv documentary and written a major piece for the Daily Mail ('The Cannbis Catastrophe') on cannabis psychosis which states that 'cannbis users today are playing russian roulette with their mental health.')
The article is one of the most prominent yet to investigate what has now become a popular media story. But is there any truth in it ? Read the article and see how you feel at the end of it. There's an awful lot of ifs and buts, arguments for and against and, I would say, an unproved causal link between smoking cannabis and psychotic behaviour (particularly schizophrenia). You may disagree.
But you should know this. One of the central planks of the 'cannbis psychosis' argument is that the strength of modern cannabis ('skunk' in particular) has increased dramatically and that this is the principal cause of the problem.
Blake Morrison wrote the following: ...'whereas 30 years ago an average joint contained about 10mg of THC, a joint of skunk today might contain as much as 300mg.'
So it was with some surprise that one read the Letters page of The Guardian a few days later (19 December) to read the communication from Dr Leslie King, former head of the drugs intelligence unit of the Forensic Science Service. King had co-authored a report for the European Monitoring Centre for Drugs and Drug Addiction which had specifically studied trends in cannabis potency in the UK and the EU. (the full report is available here for download)
The report clearly states: 'Statements in the popular media that the potency of cannabis has increased by ten times or more in recent decades are not supported by the data from either the USA or Europe.'
In his letter he writes that 'the amount of herbal cannabis or cannbis resin found in reefer cigarettes has not changed significantly in more than 20 years. The average weight of a cannabis in an unsmoked reefer has remained at around 200mg to 250mg. In other words, not only does a typical joint not contain 300mg of THC, it doesn't even contain 300mg of cannabis. A joint made from 'skunk' with a typical potency of 12% would contain around 30mg, not 300mg THC.' OOPS!!
Dr King traces the origin of this myth of super-strength cannabis back to Alan Walters, the then US drug czar, whose comments to this effect were published in The Washington Post five years ago. He says the same misinformation is on the Royal College of General Practitioners site, which reports that: 'A ‘reefer’ in the 1980s contained about 10mg of 9-tetrahydrocannabinol (THC), the main active chemical, where as a ‘joint’ today may contain around 300mg THC.' [The reference given for that is hardly up to date: 'Marijuana, In 'Comprehensive Handbook of Alcohol and Drug Addiction' by MS Gold (Marcel Dekker Inc, New York (1991)]
Then, to make things even more confusing, in 'The week's questions' (The Guardian Saturday January 7) James Ramerson answered the poser 'Is cannabis getting stronger?'
His answer: 'No. The home secretary, Charles Clarke, charged the Advisory Committee on the Misuse of Drugs in March to look at the decision to declassify cannabis from class B to C. One thing he wanted to know was whether extra-strong varieties such as skunk were raising the average strength.
This idea was given credence five years ago when Alan Walters, the US drug tsar, claimed that modern grass is 10 to 20 times more potent than the benign stuff in the carefree hippy days. This, it appears, is a myth - at least in the UK and almost all of Europe. Paul Griffiths at the European Monitoring Centre for Drugs and Drug Addiction in Portugal said: "Some of the figures quoted are just nonsensical."
He co-authored a report in 2004 which reviewed data on potency. It found that the tetrahydrocannabinol (THC), the effective potency of cannabis, in Britain has stayed at around 6% for the past 30 years. Strong varieties make up only 15% of the market. The only country in Europe where potency is increasing is the Netherlands where intensively-grown cannabis has more than 50% of the market.
He argues that concentrating on potency is a red herring. " Do people who drink whisky take in more alcohol than people who drink beer?" he asked. More important is how often people smoke, how early they started and how much they put in a joint.'
And there's more. The day before the above (Jan 6) The Guardian's political editor Michael White weighed in with a story 'Clarke paves way for U-turn on cannabis.' He wrote:
'Charles Clarke, the home secretary, was criticised yesterday from both sides of the debate on the misuse of drugs when he publicly indicated that he is considering restoring the class B status of cannabis in the light of medical evidence.
'In what the tabloids labelled a "humiliating climbdown" from the decision of his predecessor, David Blunkett, to downgrade the widely used drug to class C, Mr Clarke used media interviews to signal his approval of an imminent report, which he has already read, from the Advisory Council on the Misuse of Drugs.
'Without divulging the report's contents Mr Clarke said he would accept one recommendation - to increase education about the dangerous effects of cannabis and its legal status, after Mr Blunkett's decision two years ago caused anti-drug partisans to claim that the drug had been '"decriminalised".
'In an interview with The Times the home secretary confirmed what his officials have been saying, that new medical evidence has prompted a number of people to change their minds. "I'm very struck by the advocacy of a number of people who have been proposers of the reclassification of cannabis that they were wrong," he said. "I am also very worried about the most recent medical evidence."
The following day, The Guardian recieved the following response:
'The worst kept secret in the drugs field is that, after a detailed scrutiny of the evidence, the Advisory Council on the Misuse of Drugs does not advise the reclassification of cannabis to class B and recommends it remains in class C (Clarke paves way for U-turn on cannabis, January 6). If the government's own group of experts is clear about this it begs the question: why are politicians flying so many kites?
So how come the political editor didn't know that.
In conclusion, most readers will have read Blake Morrison's big splash G2 piece but many will have missed the letters and corrections. Thus are myths perpetuated.
On a lighter note, researchers at Columbia University claimed to have uncovered the machinery of The 'Marijuana Munchies'. See story here.
[H.J.Jo et al.: "Integration Of Endocannabinoid and Leptin Signaling in an Appetite-Related Neural Circuit." Publishing in Neuron, Vol. 48, 1055–1066, December 22, 2005, DOI 10.1016/j.neuron.2005.10.021 www.neuron.org.]
THE SATIVEX PAPERS
The UK company GW Pharmaceuticals was founded in early 1998 and recieved its first Home Office licenses to cultivate, possess and supply cannabis for research purposes were received in June that year with cultivation beginning in August.
In November 1998, the House of Lords Select Committee on Science and Technology published its report "Cannabis: The Scientific and Medical Evidence" which recommended that clinical trials of cannabis medicines should be carried out as a matter of urgency. The Committee warmly welcomed GW's research programme.
Sativex is GW's lead cannabis-based medicine which contains tetrahydrocannabinol and cannabidiol and is taken as a spray into the mouth. It does not contain the active substance found in recreational cannabis and so patients taking Sativex will not become intoxicated.
In April 2005 Sativex received regulatory approval in Canada for the symptomatic relief of neuropathic pain in adults with multiple sclerosis. The law in Canada is such that as soon as Sativex is launched in Canada, doctors will be able to prescribe it legally.
Sativex has recenty been given the go-ahead to enter final stage trials in the US to treat severe pain in cancer patients . A spokesman for the GW Pharmaceuticals said: "This is a major step. The US is the world's largest pharmaceutical market." The trial, which will involve about 250 patients, will establish whether the drug relieves pain in patients suffering from an advanced form of cancer who do not experience relief from opioid drugs such as morphine.
To meet demands for Sativex, GW Pharmaceuticals has increased production of cannabis at its fortified greenhouses to 60t/y.
In the UK however, the company is still conducting trials to try and gain approval for using it to treat muscle tightness in multiple sclerosis patients - approval which may be harder to get following an inquest into the death of a 70-year old woman who had ben involved in earlier trials of the drug.
Here are the 'Notes to Editors' on the GW site in response to the coroner's verdict:
'The inquest into the death of Mrs Rene Anderson commenced on 12 December 2005. Mrs Anderson was 69 years old with a 25 year history of diabetes mellitus, and also suffered from resistant hypertension, clinically significant depression and hyperlipidaemia. She died in March 2004.
One of the factors in her case, which has received media attention, is that Mrs Anderson had taken part in a Sativex clinical trial over a three week period during October 2003. Mrs Anderson’s total exposure to Sativex extended to a total of 42 doses (a total of less than four days worth for a typical patient). During October 2003, Mrs Anderson developed confusion and other intoxication effects and stopped taking Sativex. At the end of October 2003, a full four months before her death, a urine test confirmed that there was no presence of cannabinoids in her body.
A further period of four months of hospital inpatient care passed prior to Mrs Anderson’s death in March 2004 after pneumonia and kidney failure, during which time she received numerous medications under the direction of various doctors.
There were a number of other potential causes of confusion in this patient. Mrs Anderson was also taking a wide range of other medication both before and after her brief involvement in the Sativex trial, including tramadol, haloperidol, nitrazepam, simvastin, citalopram, losartan, frusemide, atenolol and doxazosin. All these medicines have side effects of their own, and a number list confusion on the product label. There are over 50 prescription medicines which list confusion as a side effect.'
In his verdict at the end of the inquest today, the Coroner stated that “Mrs Anderson died on 3rd March 2004 in the Northern General Hospital as a consequence of prolonged immobility following an illness for which she had been admitted on 28th October 2003. On the balance of probabilities, an idiosyncratic reaction to a trial drug (either alone or in combination with other medications) was at least a significant contributory factor to the initiation of this illness.”
According to Drug Development-Technology.Com: '...queries from the [UK] regulators have seen approval repeatedly delayed and raised the question of whether Sativex will ever be approved in the UK. GW Pharmaceuticals and Bayer will not seek wider European approval until UK regulators have given the green light.'
'Estimates suggest that between 10% and 30% of MS patients in Europe smoke cannabis to ease the pain and disabling symptoms of the disease. This activity is illegal and patients run the risk of prosecution. In the UK, cannabis-based medicines were in fact outlawed in 1968 after legislation banned doctors from prescribing tincture of cannabis.'
They conclude with a Marketing Commentary: 'In Europe alone there are some 500,000 MS patients on top of the 4 million experiencing neuropathic pain. This fact, together with a market poorly served by currently available drugs, presents an excellent opportunity for Sativex if the encouraging results seen in multiple sclerosis are reproduced in other patient groups. Regulatory approval of Sativex will set an important precedent for the use of cannabis-derived drugs.'
According to 'Marijuana May Make Your Brain Grow.' [Nature 13.10.05], neuropsychologist Xia Zhang and a team of researchers based at the University of Saskatchewan in Saskatoon, Canada, aimed to find out just how marijuana-like drugs, known collectively as cannabinoids, act on the brain.
The researchers injected rats with HU210, a synthetic drug that is about one-hundred times as powerful as THC, the high-inducing compound naturally found in marijuana. They then used a chemical tracer to watch new cells growing in the hippocampus. They found that HU210 seemed to induce new brain cell growth, just as some antidepressant drugs do, they report in the Journal of Clinical Investigation1. This suggests that they could potentially be used to reduce anxiety and depression, Zhang says. He adds that the research might help to create new cannabinoid-based treatments.
"I think it's a very exciting study," says Amelia Eisch, an addiction researcher at the University of Texas Southwestern Medical Center in Dallas. "It makes marijuana look more like an antidepressant and less like a drug of abuse."
Although his findings point to potential benefits of smoking pot, Zhang says that he does not endorse its use. "Marijuana has been used for medicine and recreation for thousands of years," he says. "But it can also lead to addiction." He says his group's next studies will examine this more unpleasant side of the drug.
at 8:30 pm